Cessna: 210M; Failed Landing Gear Warning Horn; ATA 3260

Cessna: 210M; Failed Landing Gear Warning Horn; ATA 3260

(The following discrepancies are provided by Aerospace Engineer Francisco Osciak who works for the National Airworthiness Directorate of Argentina. Oklahoma’s 105-degree, 70 percent humidity weather contrasts starkly with his e-mail description of their corresponding winter weather: 62 degrees and 65 percent humidity. Get me a ticket!).

“During landing, the pilot (of this aircraft) forgot to extend the landing gear—a gear up landing was carried out. An accident investigation included a satisfactory operational check of the landing gear retraction/extension system, but the warning horn failed to operate. After disassembling the Warning Unit Assembly, a burned diode was discovered. (Warning Assembly P/N: 1270733-2, figure 135 of Parts Catalog P637-12, index number 34. Diode P/N: IN4001, page 20-148 of Service Manual D2057-3-13.)

“We then consulted the applicable Service Manual (D2057-3-13, pages 2-28 and 2-29) and realized there is not a specific item to check the operation of the gear warning horn. This situation (no operational check of the horn) also takes place in the Cessna 172RG, 177RG, and 182 RG Service Manuals. (However...) this kind of item (operational check) does exist in many other service manuals. For example, on the 310F through 310K Service Manual, page 1-16G it is stated: ‘Gear Indicator Light and Warning Horn—check for operation (gear extended
and retracted)’.

“Taking into account all of the above, we respectfully think Cessna should revise the 172RG, 177RG, 182RG, 210, and T210 Service Manuals (or issue a Temporary Revision to each one) in order to include an inspection item requiring the operational check of the gear warning horn....” (You would make a great editor, Francisco. I’ll see what I can do at my end to help this along. Thanks—Ed.)